A giant spider breathes fire into the cloudy night sky over Glastonbury’s Arcadia stage as thumping beats from electronic music duo the Chemical Brothers excite hundreds of fans. The colossal metal arachnid, made from recycled military hardware, has been a fixture at England’s world-famous music festival for years, but this time Arcadia and all the other stages at Glastonbury are being powered entirely by renewable energy sources, organisers say. The sprawling festival, which features hundreds of acts and a colourful, unending melange of art, has long advocated sustainability and was once home to one of the UK’s largest private solar power plants. This year, all its generators, including those that power its main Pyramid stage will run on hydrotreated vegetable oil, a renewable substitute for diesel made from waste cooking oil, organisers said. “With the current infrastructure that festivals run on, it was clear one of the more efficient ways it could be done is by using a waste fuel to power all those bits of machinery,” the Arcadia stage co-founder Bertie Cole told British monthly DJ Mag. “It’s been an ongoing experiment, and this year it just felt like we had got there.” For a festival that prides itself on its social consciousness, Glastonbury has faced criticism for its impact on the environment, including the piles of rubbish left behind by many of its 200,000 attendees, despite organisers imploring them to “leave no trace”.